xref: /linux/include/linux/tee_core.h (revision 38057e323657695ec8f814aff0cdd1c7e00d3e9b)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2024 Linaro Limited
4  */
5 
6 #ifndef __TEE_CORE_H
7 #define __TEE_CORE_H
8 
9 #include <linux/cdev.h>
10 #include <linux/device.h>
11 #include <linux/dma-buf.h>
12 #include <linux/idr.h>
13 #include <linux/kref.h>
14 #include <linux/list.h>
15 #include <linux/scatterlist.h>
16 #include <linux/tee.h>
17 #include <linux/tee_drv.h>
18 #include <linux/types.h>
19 #include <linux/uuid.h>
20 
21 /*
22  * The file describes the API provided by the generic TEE driver to the
23  * specific TEE driver.
24  */
25 
26 #define TEE_SHM_DYNAMIC		BIT(0)  /* Dynamic shared memory registered */
27 					/* in secure world */
28 #define TEE_SHM_USER_MAPPED	BIT(1)  /* Memory mapped in user space */
29 #define TEE_SHM_POOL		BIT(2)  /* Memory allocated from pool */
30 #define TEE_SHM_PRIV		BIT(3)  /* Memory private to TEE driver */
31 #define TEE_SHM_DMA_BUF		BIT(4)	/* Memory with dma-buf handle */
32 #define TEE_SHM_DMA_MEM		BIT(5)	/* Memory allocated with */
33 					/* dma_alloc_pages() */
34 
35 #define TEE_DEVICE_FLAG_REGISTERED	0x1
36 #define TEE_MAX_DEV_NAME_LEN		32
37 
38 enum tee_dma_heap_id {
39 	TEE_DMA_HEAP_SECURE_VIDEO_PLAY = 1,
40 	TEE_DMA_HEAP_TRUSTED_UI,
41 	TEE_DMA_HEAP_SECURE_VIDEO_RECORD,
42 };
43 
44 /**
45  * struct tee_device - TEE Device representation
46  * @name:	name of device
47  * @desc:	description of device
48  * @id:		unique id of device
49  * @flags:	represented by TEE_DEVICE_FLAG_REGISTERED above
50  * @dev:	embedded basic device structure
51  * @cdev:	embedded cdev
52  * @num_users:	number of active users of this device
53  * @c_no_user:	completion used when unregistering the device
54  * @mutex:	mutex protecting @num_users and @idr
55  * @idr:	register of user space shared memory objects allocated or
56  *		registered on this device
57  * @pool:	shared memory pool
58  */
59 struct tee_device {
60 	char name[TEE_MAX_DEV_NAME_LEN];
61 	const struct tee_desc *desc;
62 	int id;
63 	unsigned int flags;
64 
65 	struct device dev;
66 	struct cdev cdev;
67 
68 	size_t num_users;
69 	struct completion c_no_users;
70 	struct mutex mutex;	/* protects num_users and idr */
71 
72 	struct idr idr;
73 	struct tee_shm_pool *pool;
74 };
75 
76 /**
77  * struct tee_driver_ops - driver operations vtable
78  * @get_version:	returns version of driver
79  * @open:		called for a context when the device file is opened
80  * @close_context:	called when the device file is closed
81  * @release:		called to release the context
82  * @open_session:	open a new session
83  * @close_session:	close a session
84  * @system_session:	declare session as a system session
85  * @invoke_func:	invoke a trusted function
86  * @object_invoke_func:	invoke a TEE object
87  * @cancel_req:		request cancel of an ongoing invoke or open
88  * @supp_recv:		called for supplicant to get a command
89  * @supp_send:		called for supplicant to send a response
90  * @shm_register:	register shared memory buffer in TEE
91  * @shm_unregister:	unregister shared memory buffer in TEE
92  *
93  * The context given to @open might last longer than the device file if it is
94  * tied to other resources in the TEE driver. @close_context is called when the
95  * client closes the device file, even if there are existing references to the
96  * context. The TEE driver can use @close_context to start cleaning up.
97  */
98 struct tee_driver_ops {
99 	void (*get_version)(struct tee_device *teedev,
100 			    struct tee_ioctl_version_data *vers);
101 	int (*open)(struct tee_context *ctx);
102 	void (*close_context)(struct tee_context *ctx);
103 	void (*release)(struct tee_context *ctx);
104 	int (*open_session)(struct tee_context *ctx,
105 			    struct tee_ioctl_open_session_arg *arg,
106 			    struct tee_param *param);
107 	int (*close_session)(struct tee_context *ctx, u32 session);
108 	int (*system_session)(struct tee_context *ctx, u32 session);
109 	int (*invoke_func)(struct tee_context *ctx,
110 			   struct tee_ioctl_invoke_arg *arg,
111 			   struct tee_param *param);
112 	int (*object_invoke_func)(struct tee_context *ctx,
113 				  struct tee_ioctl_object_invoke_arg *arg,
114 				  struct tee_param *param);
115 	int (*cancel_req)(struct tee_context *ctx, u32 cancel_id, u32 session);
116 	int (*supp_recv)(struct tee_context *ctx, u32 *func, u32 *num_params,
117 			 struct tee_param *param);
118 	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
119 			 struct tee_param *param);
120 	int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
121 			    struct page **pages, size_t num_pages,
122 			    unsigned long start);
123 	int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
124 };
125 
126 /**
127  * struct tee_desc - Describes the TEE driver to the subsystem
128  * @name:	name of driver
129  * @ops:	driver operations vtable
130  * @owner:	module providing the driver
131  * @flags:	Extra properties of driver, defined by TEE_DESC_* below
132  */
133 #define TEE_DESC_PRIVILEGED	0x1
134 struct tee_desc {
135 	const char *name;
136 	const struct tee_driver_ops *ops;
137 	struct module *owner;
138 	u32 flags;
139 };
140 
141 /**
142  * struct tee_protmem_pool - protected memory pool
143  * @ops:		operations
144  *
145  * This is an abstract interface where this struct is expected to be
146  * embedded in another struct specific to the implementation.
147  */
148 struct tee_protmem_pool {
149 	const struct tee_protmem_pool_ops *ops;
150 };
151 
152 /**
153  * struct tee_protmem_pool_ops - protected memory pool operations
154  * @alloc:		called when allocating protected memory
155  * @free:		called when freeing protected memory
156  * @update_shm:		called when registering a dma-buf to update the @shm
157  *			with physical address of the buffer or to return the
158  *			@parent_shm of the memory pool
159  * @destroy_pool:	called when destroying the pool
160  */
161 struct tee_protmem_pool_ops {
162 	int (*alloc)(struct tee_protmem_pool *pool, struct sg_table *sgt,
163 		     size_t size, size_t *offs);
164 	void (*free)(struct tee_protmem_pool *pool, struct sg_table *sgt);
165 	int (*update_shm)(struct tee_protmem_pool *pool, struct sg_table *sgt,
166 			  size_t offs, struct tee_shm *shm,
167 			  struct tee_shm **parent_shm);
168 	void (*destroy_pool)(struct tee_protmem_pool *pool);
169 };
170 
171 /**
172  * tee_device_alloc() - Allocate a new struct tee_device instance
173  * @teedesc:	Descriptor for this driver
174  * @dev:	Parent device for this device
175  * @pool:	Shared memory pool, NULL if not used
176  * @driver_data: Private driver data for this device
177  *
178  * Allocates a new struct tee_device instance. The device is
179  * removed by tee_device_unregister().
180  *
181  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
182  */
183 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
184 				    struct device *dev,
185 				    struct tee_shm_pool *pool,
186 				    void *driver_data);
187 
188 /**
189  * tee_device_register() - Registers a TEE device
190  * @teedev:	Device to register
191  *
192  * tee_device_unregister() need to be called to remove the @teedev if
193  * this function fails.
194  *
195  * @returns < 0 on failure
196  */
197 int tee_device_register(struct tee_device *teedev);
198 
199 /**
200  * tee_device_unregister() - Removes a TEE device
201  * @teedev:	Device to unregister
202  *
203  * This function should be called to remove the @teedev even if
204  * tee_device_register() hasn't been called yet. Does nothing if
205  * @teedev is NULL.
206  */
207 void tee_device_unregister(struct tee_device *teedev);
208 
209 int tee_device_register_dma_heap(struct tee_device *teedev,
210 				 enum tee_dma_heap_id id,
211 				 struct tee_protmem_pool *pool);
212 void tee_device_put_all_dma_heaps(struct tee_device *teedev);
213 
214 /**
215  * tee_device_get() - Increment the user count for a tee_device
216  * @teedev: Pointer to the tee_device
217  *
218  * If tee_device_unregister() has been called and the final user of @teedev
219  * has already released the device, this function will fail to prevent new users
220  * from accessing the device during the unregistration process.
221  *
222  * Returns: true if @teedev remains valid, otherwise false
223  */
224 bool tee_device_get(struct tee_device *teedev);
225 
226 /**
227  * tee_device_put() - Decrease the user count for a tee_device
228  * @teedev: pointer to the tee_device
229  */
230 void tee_device_put(struct tee_device *teedev);
231 
232 /**
233  * tee_device_set_dev_groups() - Set device attribute groups
234  * @teedev:	Device to register
235  * @dev_groups: Attribute groups
236  *
237  * Assigns the provided @dev_groups to the @teedev to be registered later
238  * with tee_device_register(). Calling this function is optional, but if
239  * it's called it must be called before tee_device_register().
240  */
241 void tee_device_set_dev_groups(struct tee_device *teedev,
242 			       const struct attribute_group **dev_groups);
243 
244 /**
245  * tee_session_calc_client_uuid() - Calculates client UUID for session
246  * @uuid:		Resulting UUID
247  * @connection_method:	Connection method for session (TEE_IOCTL_LOGIN_*)
248  * @connectuon_data:	Connection data for opening session
249  *
250  * Based on connection method calculates UUIDv5 based client UUID.
251  *
252  * For group based logins verifies that calling process has specified
253  * credentials.
254  *
255  * @return < 0 on failure
256  */
257 int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
258 				 const u8 connection_data[TEE_IOCTL_UUID_LEN]);
259 
260 /**
261  * struct tee_shm_pool - shared memory pool
262  * @ops:		operations
263  * @private_data:	private data for the shared memory manager
264  */
265 struct tee_shm_pool {
266 	const struct tee_shm_pool_ops *ops;
267 	void *private_data;
268 };
269 
270 /**
271  * struct tee_shm_pool_ops - shared memory pool operations
272  * @alloc:		called when allocating shared memory
273  * @free:		called when freeing shared memory
274  * @destroy_pool:	called when destroying the pool
275  */
276 struct tee_shm_pool_ops {
277 	int (*alloc)(struct tee_shm_pool *pool, struct tee_shm *shm,
278 		     size_t size, size_t align);
279 	void (*free)(struct tee_shm_pool *pool, struct tee_shm *shm);
280 	void (*destroy_pool)(struct tee_shm_pool *pool);
281 };
282 
283 /*
284  * tee_shm_pool_alloc_res_mem() - Create a shm manager for reserved memory
285  * @vaddr:	Virtual address of start of pool
286  * @paddr:	Physical address of start of pool
287  * @size:	Size in bytes of the pool
288  *
289  * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
290  */
291 struct tee_shm_pool *tee_shm_pool_alloc_res_mem(unsigned long vaddr,
292 						phys_addr_t paddr, size_t size,
293 						int min_alloc_order);
294 
295 /**
296  * tee_shm_pool_free() - Free a shared memory pool
297  * @pool:	The shared memory pool to free
298  *
299  * The must be no remaining shared memory allocated from this pool when
300  * this function is called.
301  */
302 static inline void tee_shm_pool_free(struct tee_shm_pool *pool)
303 {
304 	pool->ops->destroy_pool(pool);
305 }
306 
307 /**
308  * tee_protmem_static_pool_alloc() - Create a protected memory manager
309  * @paddr:	Physical address of start of pool
310  * @size:	Size in bytes of the pool
311  *
312  * @returns pointer to a 'struct tee_protmem_pool' or an ERR_PTR on failure.
313  */
314 struct tee_protmem_pool *tee_protmem_static_pool_alloc(phys_addr_t paddr,
315 						       size_t size);
316 
317 /**
318  * tee_get_drvdata() - Return driver_data pointer
319  * @returns the driver_data pointer supplied to tee_register().
320  */
321 void *tee_get_drvdata(struct tee_device *teedev);
322 
323 /**
324  * tee_shm_alloc_priv_buf() - Allocate shared memory for private use by specific
325  *                            TEE driver
326  * @ctx:	The TEE context for shared memory allocation
327  * @size:	Shared memory allocation size
328  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
329  */
330 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
331 
332 struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
333 				      size_t page_count);
334 
335 int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
336 			     int (*shm_register)(struct tee_context *ctx,
337 						 struct tee_shm *shm,
338 						 struct page **pages,
339 						 size_t num_pages,
340 						 unsigned long start));
341 void tee_dyn_shm_free_helper(struct tee_shm *shm,
342 			     int (*shm_unregister)(struct tee_context *ctx,
343 						   struct tee_shm *shm));
344 
345 /**
346  * tee_shm_is_dynamic() - Check if shared memory object is of the dynamic kind
347  * @shm:	Shared memory handle
348  * @returns true if object is dynamic shared memory
349  */
350 static inline bool tee_shm_is_dynamic(struct tee_shm *shm)
351 {
352 	return shm && (shm->flags & TEE_SHM_DYNAMIC);
353 }
354 
355 /**
356  * tee_shm_put() - Decrease reference count on a shared memory handle
357  * @shm:	Shared memory handle
358  */
359 void tee_shm_put(struct tee_shm *shm);
360 
361 /**
362  * tee_shm_get_id() - Get id of a shared memory object
363  * @shm:	Shared memory handle
364  * @returns id
365  */
366 static inline int tee_shm_get_id(struct tee_shm *shm)
367 {
368 	return shm->id;
369 }
370 
371 /**
372  * tee_shm_get_from_id() - Find shared memory object and increase reference
373  * count
374  * @ctx:	Context owning the shared memory
375  * @id:		Id of shared memory object
376  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
377  */
378 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
379 
380 static inline bool tee_param_is_memref(struct tee_param *param)
381 {
382 	switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
383 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
384 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
385 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
386 		return true;
387 	default:
388 		return false;
389 	}
390 }
391 
392 /**
393  * teedev_open() - Open a struct tee_device
394  * @teedev:	Device to open
395  *
396  * @return a pointer to struct tee_context on success or an ERR_PTR on failure.
397  */
398 struct tee_context *teedev_open(struct tee_device *teedev);
399 
400 /**
401  * teedev_close_context() - closes a struct tee_context
402  * @ctx:	The struct tee_context to close
403  */
404 void teedev_close_context(struct tee_context *ctx);
405 
406 /**
407  * teedev_ctx_get() - Increment the reference count of a context
408  * @ctx: Pointer to the context
409  *
410  * This function increases the refcount of the context, which is tied to
411  * resources shared by the same tee_device. During the unregistration process,
412  * the context may remain valid even after tee_device_unregister() has returned.
413  *
414  * Users should ensure that the context's refcount is properly decreased before
415  * calling tee_device_put(), typically within the context's release() function.
416  * Alternatively, users can call tee_device_get() and teedev_ctx_get() together
417  * and release them simultaneously (see shm_alloc_helper()).
418  */
419 void teedev_ctx_get(struct tee_context *ctx);
420 
421 /**
422  * teedev_ctx_put() - Decrease reference count on a context
423  * @ctx: pointer to the context
424  */
425 void teedev_ctx_put(struct tee_context *ctx);
426 
427 #endif /*__TEE_CORE_H*/
428